GM Service Manual Online
For 1990-2009 cars only
Table 1: Body Control Module
Table 2: Engine Control Module (ECM)

Body Control Module

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON, with the engine OFF. Transmission shift lever in the PARK position.

Brake Applied Output Signal

Data / Outputs

ON / OFF

OFF

Shift Lock Solenoid Command

Data / Outputs

ON / OFF

ON

Shifter Unlock Command

Data / Outputs

ON / OFF

OFF

Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Operating Conditions: Ignition ON, with the engine OFF. Transmission shift lever in the PARK position.

Ignition Voltage

Auto Transmission Data

Volts

0-25v

IMS A/B/C/P

Auto Transmission Data

Park, Park/Reverse, Reverse, Reverse/Neutral, Neutral, Neutral/Drive 4, Drive 4, Drive 4/Drive 3, Drive 3, Drive 3/Drive 2, Drive 2, Drive 2/Drive 1, Drive 1, Invalid, Open

Park

Reverse Inhibit Solenoid Circuit Status

Auto Transmission Data

OK, Incomplete, Short B+, Short Gnd / Open

OK

Reverse Inhibit Solenoid Command

Auto Transmission Data

Not Equipped / ON / OFF

ON

TCC Brake Switch

Auto Transmission Data

ON/OFF

OFF